Method and apparatus for forming continuous filaments



June 26, 1962 G. SLAYTER ETAL METHOD AND APPARATUS FOR FORMINGCONTINUOUS FILAMENTS 3 Sheets-Sheet 1 Filed Aug. 12, 1959 INVENTORS6/1/1455 Sun m? &

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A T TOP/V6 r5 June 26, 1962 e. SLAYTER ETAL 3,040,377

METHOD AND APPARATUS FOR FORMING CONTINUOUS FILAMENTS Filed Aug. 12,1959 5 Sheets-Sheet 2 June 26, 1962 G. SLAYTER ETAL 3,040,377

METHOD AND APPARATUS FOR FORMING CONTINUOUS FILAMENTS 5 Sheets-Sheet 3Filed Aug. 12, 1959 INVENTORS 6M5 Sun 7m & y Foam 11/ IP07 Arrow/5Y5United States Patent 3,040 377 METHOD AND APPARATUS FGR FORMINGCONTINUOUS FILAMENTS Gaines Slayter and Roger W. Roth, Newark, Ohio,assignors to Owens-Corning Fiberglas Corporation, a corporation ofDelaware Filed Aug. 12, 1959, Ser. No. 833,247 15 Claims. (Cl. 18-8)This invention relates to a method of and apparatus for formingcontinuous filaments or fibers and more especially to the formation ofcontinuous fine filaments of heat-softenable material through theutilization of centrifugal forces.

Methods have been employed for forming filaments of materials such asglass, by attenuation as by winding the filaments in a group or strandon a rotatable collector, the collected group or strand being used inthe formation of threads and yarns particularly usable in manufacturingtextiles and the like.

Developments have been made in the production of staple filaments orfibers utilizing a rotor fashioned with a substantial number of smallopenings or orifices through which material is extruded undercentrifugal forces of rotation of the rotor and the extruded orprojected bodies of material engaged by a gaseous blast for forming thelinear bodies into fibers. In such operations' the fiberforming materialis heated to a softened or flowable condition in a furnace or feeder anda stream of the softened material delivered into the rotor for extrusionthrough the perforations or orifices.

3,040,377 Patented June 26, 1962 flowable material through aperturesunder the influence of centrifugal forces and attenuating the projectedmaterial to continuous filaments, and providing a heated atmosphere orenvironment in the region ambient thev chamber and the centrifugallyprojected material to minimize heat losses at the attenuating region andassist in the collection of the attenuated filaments.

Another object of the invention is the provision of an apparatuscomprising a rotatable chamber or rotor of comparatively small diameterheated by high frequency induction and provided with means fordistributing granular filament-forming material in a thin layer on asurface of the rotor to reduce the granular material of the layer toflowalble form, the rotor provided with open areas through which theflowable material is projected by centrifugal forces and attenuated byrotation of the rotor to form continuous filaments.

Another object of the invention is the provision of an 4 apparatuscomprising a rotatable hollow rotor of comparatively small diameteradapted to be rotated at a relatively high speed and inductively heatedby high frequency current to fuse the granular material in combinationwith means for feeding granular material to the The pesent inventionembraces the provision of a method of forming continuous fibers orfilaments wherein heat-softenable fiber-forming material is introducedinto a rotor in finely divided granular or particulate form and thefinely divided or granular material in the rotor subjected to heat in amanner to reduce the material to a liquidous flowable condition and theflowable material acted upon by centrifugal forces to form continuousfilaments. 7

Another object of the invention is the provision of a method involvingthe delivery of heat-softenable fiberforming material in a nonmoltencondition into a rotating chamber and the material reduced to a moltenor flowable state within the chamber and projected from the chamber inthe form of discrete bodies through a secondary heated environment in amanner fostering the production of continuous fine filaments from thebodies usable in the production of threads and'yarns for textile andsimilar purposes. Y l

Another object of the invention is the provision of a method of formingcontinuous filaments by forces of rotation wherein filament-formingmaterial is delivered into a rotatable chamber in a nonmolten conditionand the chamber-subjected to high frequency electrical energy to heatthe material in 'the chamber to a softened or molten condition and thesoftened material delivered from the rotating chamber and attenuated tocontinuous fine filaments.

Another object of the invention is the provision of a method of rapidlyreducing finely divided or granular glass cullet to a heat-softened,flowable state within a rapidly rotating chamber including the steps ofimping ing the granular cullet upon a rotating distributor whereby thecullet is projected to a wall of the chamber, and inductively heatingthe chamber wall to a temperature above the fusing point of the culletwhereby the cullet at the heated wall is reduced to a heat-softened ormolten,

rotor at a controlled rate and distributing the material in granularform within the rotor to continuously form a thin layer of the materialon the heated rotor surface to rapidly reduce the granular material to amolten state, the arrangement including a plenum chamber surrounding therotor arranged to deliver air at an elevated temperature and lowvelocity into an annular region into which molten material is projectedand attenuated to continuous filaments to bias the filaments toward afilament collecting means.

Another object of the invention is the provision of a rotor ofcomparatively small size maintained at a high temperature adapted toreduce granular cullet or material to a heat-softened flowable state,the rotor being provided with orifices through which the softenedmaterial is projected in the form of continuous filaments, and meansarranged to deliver air streams surrounding the rotor, the air streamsbeing of a temperature to establish an environment of greatest heatadjacent the rotor and a progressively reduced temperature gradientoutwardly from the rotor.

Another object of the invention is the provision of a rotatable meltingchamber for glass cullet in granular form wherein the rotor providingthe chamber is of small diameter and of thin walled construction wherebya minimum of metal is required for the rotor.

Another object of the invention is the provision of a method of formingfibers of heat-softenable mineral material wherein a comparatively smallamount of material is rapidly raised to attenuating temperature andimmediately converted to continuous filaments, the method'beingcontinuous whereby only the amount of material required for immediateattenuation is subjected to intense heat concomitantly with theattenuating operation.

Further objects and advantages are within the scope of this inventionsuch as relate to the arrangement, operation and function of the relatedelements of the structure, to various details of construction and tocombinations of parts, elements per se, and to economies of manufactureand numerous other features as will be apparent from a consideration ofthe specification and drawing of a form of the invention which maybepre- 'ferred, in which:

FIGURE 1 is a semi-diagrammatic elevational view illustrating a form ofapparatus for performing steps in the method of the invention;

FIGURE 2 is a vertical sectional view through the arrangementillustrated in FIGURE 1;

FIGURE 3 is a horizontal sectional view taken substantially on the line3-3 of FIGURE 2;

FIGURE 4 is a vertical sectional view illustrating a rotor constructionof the invention associated with external heating means and anarrangement for applying heat internally of the rotor;

FIGURE 5 is a fragmentary sectional view similar to FIGURE 2illustrating a modified form of means for establishing a mobileenvironment of heated air adjacent and surrounding the rotor, and

FIGURE 6 is an elevational view showing amodified form of rotor.

While the method and apparatus of the invention are especially usablefor forming fine continuous filaments or fibers of glass cullet, it isto be understood that the invention may be utilized for formingcontinuous filaments from other heat-softenable mineralrmaterials orfilamentforming resins or polymers. 7

With particular reference to the apparatus shown in FIGURES 1 through 3,and initially to FIGURE 1, there is illustrated a support or frameconstruction 10 comprising a main mounting plate 12 to which are securedvertical struts 14 supporting horizontally extending members 16. Theplate 12 is provided with a bracket or member 18 which supports anelectrical energized motor 20 arranged to rotate the rotor.

Supported upon the mounting plate 12 is a supplemental frameconstruction 24 having upper and lower members or plates 26 and 28supporting anti-friction or ball bearings 38 and 32. Journally supportedon the bearings 3a and 32 is a rotatable structure including a hollowsleeve 36 of generally circular cylindrical shape formed-with atruncated cone shaped or flaring portion 33 joined with a dependingcylindrical wall portion '40 adapted to support the rotor construction.

With particular reference to FIGURE 2, the rotor or rotor construction44 is of tubular thin walled configuration comprising a verticallydisposed circular cylindrical wall 46 and bottom wall 48, the rotorbeing made of platinum rhodium alloy or other material which willwithstand high temperatures. The upper end of the wall 46 is formed withan outwardly extending circular flange 52 and an inwardly extendingflange 51). Means is provided for connecting the rotor 44 with thecylindrical sleeve portion 40.

As shown in FIGURE 2, a coupling or collar 54 of cylindrical shape isfashioned with an inwardly extending flange 56 which is joined to theflange 52 of the rotor by means of pins 58 or other suitable securingmeans adapted to establish a drive connection between the rotor 44 andthe coupling member 54. The depending sleeve portion 4% is formed withcircumferentially spaced bayonet-type slots 62 and the upper region ofthe coupling member 54 provided with pins 64 adapted to estabnection.The sleeve 36 is equipped with pulley 70 engaged by a driving belt 72driven by the motor 24 through a motor driven pulley 74 as shown inFIGURE 1.

The circular cylindrical wall 46 of the rotor 44 is of comparativelysmall diameter, for example, 1 /4" inside diameter whereby the rotor maybe driven or rotated at a comparatively high speed to set up orestablish centrifugal forces of suflicient magnitude to 'eifectively andefficiently project heat-softened mobile material within the rotorthrough rows of small orifices 49 formed in the lower region of thecylindrical rotor wall 46. Any number of small orifices 49 may beemployed, dependent upon the number of continuous filaments to beformed.

The orifices 49 are of small size in order to provide for the formationof fine continuous filaments from the streams of heat-softened materialmoving through the orifices. If a greater number of continuous filamentsis desired to be produced from one rotor, a greater number of orificesmay be employed by increasing the diameter of the rotor wall 46 oremploying a rotor of increased length.

An important feature of the method of the invention resides in thedelivery into the rotor of fiber-forming material in finely divided,particulate or granular condition at normal temperature and the granularmaterial distributed onto the rotor wall 46 which is heated andmaintained at a temperature sufiiciently high to rapidly fuse or reducethe particles or granules to a heat-softened mobile or molten condition.The fiber-forming material is delivered in particulate or granular forminto the interior of the rotor through the hollow sleeve 36. Disposedwithin the rotating sleeve 36 is a stationary guide means for directingthe particulate or granular material into the rotor.

. As shown particularly in FIGURE 2, the guide means comprises a tube 76surrounded by a jacket 73 having a closed lower end 79 to accommodate acooling fluid. This arrangement provides an elongated annular chamber 80to accommodate a circulating cooling fluid which is introduced into thechamber through an inlet 82 and conveyed away from the chamber by anoutlet 84. The circulation of cooling fluid through the chamber 80 iseffective to maintain the guide tube 76 and the sleeve 36 at safeoperating temperatures.

Means is provided for feeding the particulate or granular material suchas crushed glass cullet into the guide means 76. As shown in FIGURE 1, ahopper 86, adapted to contain a supply of the particulate or granularmaterial, is disposed above a funnel or chute 88 supported by the framestructure 10, the chute 88 being adapted to direct the fiber-formingmaterial into the guide tube 76. The hopper 86 is formed with adischarge tube 90 in registration with the chute 88 for deliveringmaterial into the funnel 88.

Means is provided associated with the hopper 86 for controlling orregulating the rate of feed or delivery of the particulate or granularmaterial into the rotor. As shown in FIGURE 1, the hopper 86, at itsregion of connection with the discharge tube 90, is formed with acylindrically shaped portion 92 in which is journalled a shaft 93carrying a feed drum 94 provided with radially arranged vanes 95, thevanes having rotating clearance with the cylindrical portion 92 of thehopper. The rotating vanes 95 engage material in the hopper and conveysuccessive metered quantities of material into the tube 90.

A sprocket on the shaft 93 is connected by means of driving chain 98with a sprocket 99 associated with speed reducing gearing contained in ahousing 100, the gearing being operated by an electric motor 102 fordriving the material feed or metering drum 94. The gearing within thehousing 106} maybe of the variable speed type to vary the rate ofrotation of the feed drum, or other suitable variable speed drivingmeans may be utilized for rotating the drum 94.

Positioned within the rotor 44 is a platform or material distributingmember 106 preferably slightly frusto-conical in shape, as shown inFIGURE 2, the platform being of circular contour and supported byradially extending struts or bars 108, shown in FIGURE 3, welded orotherwise joined'to the inner surface of the vertical rotor wall 46 andto the peripheral region of the distributing plate 106, the member 106being rotatable with the rotor.

The struts 1% are fashioned comparatively thin so as not to appreciablyimpair or impede the formation of a V film of heat-softened material onthe inner cylindrical surface of the rotor wall 46. The finely dividedmaterial M descending by gravity through the guide tube 76, as shown inFIGURE 2, impinges or engages the rotating distributing plate 106, theparticulate or granular material being projected outwardly bycentrifugal forces into contact with the inner surface of the verticalwall 46 of the rotor. In the arrangement illustrated in the drawings,comparatively high frequency electric current is employed forinductively heating the rotor or spinner to a temperature sufiicientlyhigh to rapidly fuse or reduce the particulate or granular material to aheat-softened flowable condition whereby a film of mobile heat-softenedor molten material is provided and continuously maintained on theinterior surface of the rotor wall 46. As shown in FIG- URES l, 2 and 3,an induction heating coil 110 surrounds the vertical wall 46 of therotor at a region just,

of the coil are hollow .and are water cooled. The convolutions of thecoil 110 are provided with a sheath or coating of glass fibers and resinto insulate the convolutions, one from another. By supplying highfrequency current to the coil 110 the rotating rotor 44 is heated to atemperature of twentyfive hundred degrees Fahrenheit or more,sufficiently high to fuse or soften the granular material collecting onthe 'vertical wall 46.

The rotor 44 is rotated at a speed of upwards of seven thousandrevolutions or more per minute depending upon the diameter of the rotorand the desired magnitude of centrifugal forces set up by rotationacting upon the film of flowable softened glass at the region of theorifices 49 whereby the softened material is projected outwardly andattenuated by the centrifugal forces and the rotative movement of therotor to form fine continuous filaments F.

The filaments are directed downwardly by means hereinafter described andare brought together at a region 120 to form a twisted multifilamentstrand, thread or yarn 122 which may be collected upon a rotatingcollector sleeve or member 124 carried by a rotating mandrel 126. Themultifilament strand may be traversed lengthwise of the collector sleeve124 by suitable conventional traverse means (not shown) to form a woundpackage.

In order to direct the discrete continuous filaments downwardly from therotor and to promote efficient attenuation an environment of heated airis provided at the exterior surface region of the rotor wall 46 and theregion occupied by the outwardly moving continuous filaments. The heatedair is continuously delivered into the environment surrounding the rotorat a comparatively low flow rate to form a downwardly moving heated airstream in the nature of a gentle breeze to gradually retard outwardmovement of the continuous filaments and assist in by brackets 131associated with member 12. The plenum chamber 132 is connected by meansof tubular means the purpose. -A lower wall 144 and an angularlyarranged or frusto-conically shaped wall 146 are provided with one ormore rows of openings 143 and 150 respectively as shown in FIGURE 2. Theopenings in the wall 146 are arranged to direct air toward the rotorwall 46 While the openings 148 in the wall 144 direct air into theenvironment occupied by the filaments moving outwardly from the rotor.

The heater 136 is adapted to heat the air delivered from the plenumchamber 132 at a temperature of about 500 F. or more and, through thismethod, the filaments move through a heated environment as they areattenuated, the heated environment assisting in retarding or minimizingheat losses from the rotor. The low velocity air streams from theoutlets 148 and 150 provide a biasing force effective to influencemovement of the individual attenuated continuous filaments in adownwarddirection.

The heated environment provided by flow of air from the plenum chamber132 ispreferably surrounded by a second annular environment of heatedairof a lower temperature than that delivered from the plenum chamber132. As shown in FIGURE 2, a second annular or ring-shaped member 154,supported by the member 12,-

surrounds the plenum chamber 132 and is formed with a plenurnchamberadapted to receive atmospheric air supplied by a blower 156 through aconduit 158. The air from the blower 156 may be heated in a chamber 157by electrically energized heater strips 159 adapted to heat the air inthe chamber 155 above room temperature but at a temperature lower thanthe air delivered from the first plenum chamber 132.

Bafile members 160 are disposed in the annular manifold or chamber 155to distribute the heated air throughout the chamber. The floor or lowerWall of the chamber 155 is in the form of a perforated grill or plate162, the air from the chamber 155 being projected at a low velocitythrough the plurality of openings 164 formed in the grill or plate 162.The air flow from the chamber "155 provides an environment surroundingthe first mentioned environment of heated air at a lower temperature toassist in deflecting or directing the continuous filaments downwardly.

A cylindrically shaped shield or enclosure 16,8, secured to anddepending from the periphery of the annular manifold 154, provides abarrier or means for confining the environment of heated air, andinfluencing movement of the heated air in a downward direction causingthe continuous filaments F to be directed downwardly in directionsillustrated in FIGURES 1 and 2.

Through the arrangement of the plenum chambers 132 and 155 adapted todeliver heated air of diiferent temperatures into the circular enclosure168, a decreasing temperature gradient is established outwardly of theaxis of the rotor 44.

The method of operation of the arrangement shown in FIGURES 1 through 3is as follows: The hopper 86 is filled with heat-softenablefiber-forming material in finely divided,' particulate or granular form.Where the fiber-forming material to be employed is glass, the glass ishighly refined and previously formed into pieces or marbles which areground or crushed to granular or particulate form.

The rotor 44 is rotated by energizing the motor 20 to revolve the rotorat a speed of upwards of seven thousands revolutions per minute or moreto develop centrifugal forces efiective to cause the extrusion orprojection of heat-softened material of the film of molten material inthe rotor through the orifices 49 in the rotor wall 46.

High frequency current energizes the induction heater 111 surroundingthe rotor to heat that region of the rotor surrounded by the inductionheater to a temperature of 2500 degrees Fahrenheit or more. The blowers138 and 156 are rotated to deliver air into the heating chambers 136 and157.

The heater strips 14-2 in the chamber 136 are energized to heat the airin the unit 136 to a temperature upwards of 500 F. or more and under thepressure of the blower 138 the heated air flows through conduit 134 intothe plenum chamber 132 thence through the orifices 148 and 1511 in wallregions of the annular member 1319 providing the plenum chamber 132,whereby the heated air moves at a low velocity downwardly along therotor and in the annular region or environment surrounding the rotor.

The heater strips 159 in the chamber 157 are energized to heat the airdelivered through the perforations or outlets 164 at a lessertemperature than the air from the plenum chamber 132. The air deliveredthrough the outlets 164 is preferably between 100 and 300 degreesFahrenheit but is not limited to this temperature range. The airdelivered from the chamber 155 assists in deflecting the continuousfilaments F downwardly as well as to maintain the heated air from thechamber 132 in a region ambient the rotor to retard or prevent rapidchilling of the fiber-forming material. A second water cooled inductionheating coil 166 may be disposed interiorly of the skirt or sleeve 168surrounding and in horizontal alignment with the region of the rotorprovided with the orifices 4-9 for heating this portion of the rotor.The induction heater 166 may be energized by high frequency current fromthe generator or power supply 116.

The motor 132 is energized to operate the feed drum or rotary valve 94disposed in the lower region of the hopper 86 so as to continuouslymeter and feed the particulate or granular fiber-forming material fromthe hopper 86 into the tube WP and chute 38, through the guide tube 76and onto the platform or material distributor 106 arranged in the pathof the material moving through the tube 76. The centrifugal forces ofrotation of the distributor 106 deliver the particulate or granularmaterial outwardly into contact with the interior surface of the rotorwall 46 or in contact with material on the wall which has beenheat-softened under the intense heat of the rotor Wall generated by highfrequency current in the induction heater 110.

, Thus, the finely divided fiber-forming material at the inner surfaceof the rotor wall 46 is rapidly heated and reduced to softened, flowableor mobile form providing a thin film of molten material on the interiorsurface of the wall 46.

The inwardly extending ledge or flange 51 at the upper end of the rotorlimits the upward movement of the flowable material and under theinfluence of centrifugal forces the softened flowable material of thefilm is continuously projected or extruded outwardly through the outletsor orifices 49 as individual bodies, and under the influence ofcentrifugal forces and rotation of the rotor, the bodies of material areattenuated to fine continuous filaments F.

The gentle air currents delivered downwardly from the outlets from theplenum chambers 132. and 155 assist in deflecting the continuousfilaments downwardly. By reason of rotation of the rotor, the group ofcontinuous filaments is twisted together at the region 12%) forming alinear group, strand or yarn 122 of filaments which is collected uponthe rotating sleeve or collector 124 carried by the mandrel 126. Therate of feed of the finely divided or particulate material deliveredfrom tl e hopper 86 may be regulated and controlled through the variablespeed mechanism contained in the housing 1% of the means driving thematerial metering or feed valve 94.

Through this method and: apparatus of forming continuous filaments, thefinely divided material is delivered into intimate contact with theintensely hot rotor wall 46 and is rapidly heated to a softened andflowable condition in a zone where the heat is concentrated through theuse of high frequency current in the induction heater with a minimum ofheat loss. The heated air from the plenum chamber 1'32 assists inmaintaining the rotor at a high temperature by surrounding the rotorwith'au environment of heated air whereby a high efliciency ofattenuation is attained.

The use of a comparatively small rotor effects substantial savings inplatinum rhodium alloy which is very costly. Furthermore the methodeliminates the use of a stationary feeder containing a substantialquantity of glass which must be maintained at a high temperature tosupply streams of molten glass for attenuation purposes. Through themethod of the present invention, the glass cullet is heated in the rotorto a molten state and only the amount of cullet is heated to provide athin film of molten glass on the rotor surface to fulfill therequirements necessary to maintain continuous delivery of softened glassthrough the rotor orifices 49.

FIGURE 4 is a sectional view illustrating a modified form of rotor inconjunction with means for applying heat interiorly of the rotorsupplementing the heat derived from high frequency induction. In thisform, the rotor 170 is formed with a bottom wall 171 and a cylindrical.vertical wall 172 provided at its upper end with an outwardly extendingannular flange 173 and an inwardly extending annular flange 174. Thewall 172, at

its lower region, is provided with a plurality of rows of orifices 176through which heat-softened or molten material of the film of materialon the. inner surface of the wall 172 is projected by centrifugal forcesand attenuated to continuous filaments.

The rotor 170 is formed with an axially disposed strut 178 whichsupports a platform or material distributing member 1813 which issimilar to the material distributor 1116 shown in FIGURE 3. The materialguide tube 76a is aligned with the distributor 180 whereby fiber-formingmaterial in finely divided or particulate form delivered onto thedistributor 180 is subjected to centrifugal forces of rotation of thedistributor and thereby projected outwardly onto the inner surface ofthe rotor wall 172.

Extending downwardly into the rotor 171i is a tubular means 182 having acurved outlet or elbow portion 184 at its lower extremity, as shown inFIGURE 4, directed toward the lower peripheral region of the wall 172adjacent its juncture with the bottom wall or floor 171 of.

the rotor. The tubular means 132 is adapted to be connected with asupply of combustible mixture, such as fuel gas and air, undercomparatively low pressure which is conveyed from the supply by thetubular means for discharge from the curved or elbow portion 184 intothe rotor.

The combustible mixture is ignited at the outlet of the curved portion184 and provides heat in the lower interior peripheral region of therotor to assist in maintaining the heat-softened film of fiber-formingmaterial in the rotor in a flowable condition to facilitate its deliverythrough the orifices 176. The rotor 170 is heated by high frequencycurrent supplied to the induction heater 1151a, and the supplementalheat, provided by the burning mixture at the outlet of the portion 184,avoids any tendency of the material in the lower region of the rotorfrom becoming highly viscous, a condition which would impair the'flowability of the material.

FIGURE 5 is a fragmentary sectional view similar to a portion of FIGUREZillustrating a modified arrangement of plenum chambers for providingsuccessive environments of air at difierent temperatures at the regionof formation of the continuous filaments. In this form, the rotor 44aand its driving means are the same as the means illustrated in FIGURE 2.

ber 132a and the air discharge orifices 148a and 150a .are of the samecharacter as those shown in FIGURE 2.

The plenum chamber 132a receives heated air from the air heating unit136a whereby air at upwards of 500 F. or more is delivered into a regionsurrounding and adjacent the rotor 44a.

A second manifold 186 isdisposed adjacent manifold 130a and at a lowerlevel than the manifold 130a, the inner circular wall 188 of themanifold 186 forming a means of confining the heated air deliveredthrough the orifices 148a and 150a adjacent the rotor. The member ormanifold 186 is formed with an outer peripheral wall 190 which supportsa cylindrical sleeve, guard or baffle 1680. The member 186 is providedwith a circular partition 192 which effectively subdivide the hollowinterior of member 186 into a plenum chamber 194 and a second plenumchamber 196 which are arranged in concentric relation.

A plate 198 forms a bottom wall of both chambers and is formed with acomparatively large number of small outlets or orifices 200 throughwhich air from chambers 194 and 196 is delivered within the regiondefined by the circular sleeve l68a. The plenum chamber 194 is suppliedwith-air from a blower (not shown) the air being conducted through aheater 157a for heat-.

ing the incoming air to a temperature lower than that of the heated airsupplied to the chamber 132a.

The chamber 196 is adapted to deliver air at room temperature through atube 206 connected with a suitable We claim:

1. The method of processing heat-softenable filamentforming materialincluding the steps of feeding the material onto an elevated platform ina walled chamber, distributing the material from the platform bycentrifugal forces toward a wall of the chamber to form a thin layer ofthe material on the wall, inductively heating the chamber, reducing thematerial to molten condition by the inductive heat applied to thechamber, flowing the molten material downwardly along the wall, rotatingthe walled chamber at a 'high speed, projecting the molten material bycentrifugal forces of rotation from the chamber through openings in thechamber wall, attenuating the projected material to continuous filamentsby rotation of the chamber.

2. The method of processing heat-softenable filamentforming materialincluding the steps of feeding the ma- 7 terial in particulate formontoan elevated platform in a blower (not shown) to provide a lowvelocity air movement surrounding the heated air environment. Thechambers 194 and 196 may be provided with bafiies 209 and 21-0respectively to assist in the distribution of air in the chambers. 7

Thus, through the arrangement of plenum chambers 132a, 194 and 196adapted to deliver air at different temperatures, a temperature gradientis established in the environment surrounding the rotor withprogressively lower temperatures maintained at increased distancesoutwardly from the rotor. The highest temperature environment isestablished at the region of the rotor 44a and low velocity air streamsflowing-from the plenum chambers deflect the continuous filaments Fdownwardly.

A modified form of rotor 216 is illustrated in FIGURE 6. The rotor 216is formed with a wall 218 tapered or flared outwardly and downwardlyfrom the flange 220 to assist in biasing the 'fiow of the moltenmaterial of the.

film adjacent the inner surface 222 toward the region of the orifices224. While a single row of orifices is illustrated in FIGURE 6, it is tobe understood that a plurality of rows may be utilized dependent uponthe number of filaments desired to be formed from a single rotor.

The lower region of the rotor beneath the tapered wall 218 is formedwith a cone-shaped portion or cap 226 to reduce turbulence immediatelybeneath the rotor.

In the forms of the rotor construction, the platform or materialdistributor is at the upper region of the rotor and is substantiallyembraced by the induction heating unit so that the glass cullet isdistributed to'the rotor wall at a region of high temperature in orderto efficiently reduce the particles to molten condition. It is to beunderstood that while the method and arrangement are particularlyadapted for reducing granular or particulate filamentforming material toa softened and flowable condition, a

stream of heat softened glass or other mineral material may be deliveredthrough the guide tube onto the platform and the softened materialdistributed on the rotor wall.

It will be apparent that, within the scope of the invention,modifications and different arrangements may be made other than asherein disclosed, and the present disclosure is illustrative merely, theinvention comprehending all variations thereof.

walled chamber, distributing the material from the platform to form athin layer of the material on the wall, applying electric heat to thechamber, reducing the particles to molten condition by the heat appliedto the chamber, flowing the molten material downwardlyalong the wall,rotating the walled chamber at a high speed, projecting the moltenmaterial by centrifugal forces'of rotation outwardly from the chamberthrough openings v in the chamber wall, attenuating the projectedmaterial to continuous filaments by rotation of the chamber, andengaging the filaments by downwardly directed low velocity air streamsto modify the directions of movement of the continuous filaments.

3. The method of processing heat-softenable filament v forming materialincluding the steps of feeding the material onto an elevated platform ina walled chamber, distributing the material from the platform toward awall of the chamber to form a thinlayer of the material on the wall,applying heat to the chamber, reducing the material to molten conditionby the heat applied to the chamber, flowing themolten materialdownwardly along the wall, rotating the walled chamber at acomparatively high speed, projecting the molten material by centrifugalforces of rotation outwardly from the chamber through openings in thechamber wall, attenuating the projected material to continuous filamentsby rotation of the chamber, directing low velocity heated air streams inthe region of the continuous filaments, and deflecting the continuousfilaments downwardly and away from the chamber by the air streams.

4. The method of processing heat-softenable filamentforming materialincluding the steps of feeding the ma-.

terial from a supply at a controlled rate into contact with a movabledistributor, delivering the material from the distributor onto arotating surface to form a thin layer of the material on the surface,continuously heating and maintaining the surface at a temperature abovethe softening temperature of the material, reducing the material on thesurface to a molten condition by heat from the surface, rotating thesurface at a high speed, projecting the molten material through openingsin the rotating surface, attenuating the projected material tocontinuous filaments, and directing air streams of difierenttemperatures into the region of the continuous filaments to establish adecreasing temperature gradient outwardly from the rotating surface.

5. Themethod of processing heat-softenable filamentforming materialincluding the steps of feeding the material in particulate form from asupply at a controlled rate, delivering the material from thedistributor onto a surface to form a thin layer of the material .on thesurface, continuously heating and maintaining the surface at atemperature above the softening temperature of the material, reducingthe particles of material on the surface to a molten condition by heatfrom the surface, rotating the surface at high speed, projecting themolten material through openings in the rotating surface, attenuatingthe projected material to continuous filaments,.directing air streams atelevated temperature into the zone of the moving filaments, anddirecting air streams of lesser temperature into a zone surrounding theair streams at elevated temperature to establish a decreasingtemperature gradient outwardly of the axis of rotation .of the surface.

6. The method of processing heat-softenable filamentforming materialincluding the steps of feeding the material from a supply at acontrolled rate into contact with a movable distributor, delivering thematerial from the distributor to a wall of a chamber to form a thinlayer of the material on the wall surface, inductively heating andmaintaining the surface at a temperature above the softening temperatureof the material, reducing the material on the surface to a moltencondition by heat from the surface, rotating the chamber, projecting themolten material through openings in the wall of the chamber, attenuatingthe projected material to continuous filaments, directing air streams oflow velocity at elevated temperature into the zone of the movingfilaments adjacent the surface, and directing air streams ,of lessertemperature and of low velocity into a zone surrounding the air streamsat elevated temperature to establish a progressively decreasingtemperature gradient outwardly of the axis of rotation of the chamber.

7. The method of processing heat-softenable, filament-forming materialincluding the steps of establishing a supply of the material inparticulate form, feeding the material from the supply at a controlledrate onto an elevated platform in a walled chamber, distributing thematerial in particulate form by centrifugal force from the platform intoheat-transferring relation with the chamber Wall, heating the chamberwall inductively by high frequency current to a temperature above thesoftening temperature of the material, reducing the material to a moltencondition by heat from the wall of the chamber, flowing the moltenmaterial downwardly along the wall, rotating the walled chamber at ahigh speed, projecting the molten material through orifices in the wallunder the influence of centrifugal forces, attenuating the projectedmaterial to fine continuous filaments by rotation of the walled chamber,and directing the continuous filaments downwardly by low velocitystreams of air.

8. The method of processing heat-softenable, filamentforming materialincluding the steps of establishing a supply of the material, feedingthe material from the supply at a controlled rate onto an elevatedplatform in a walled chamber, distributing the material by centrifugalforces from the platform into heat-transferring relation with thechamber wall, continuously heating the chamber wall inductively by highfrequency current to a temperature above the softening temperature ofthe material, reducing the material to a molten condition by heat fromthe Wall of the chamber, flowing the molten material downwardly alongthe wall, rotating the Walled chamber at a high speed, applyingadditional heat to the material interiorly of the chamber, projectingthe molten-material through orifices in the wall under the influence ofcentrifugal forces, attenuating the projected material to finecontinuous filaments by rotation of the walled chamber, biasing thecontinuous filaments downwardly by concentric streams of heated air, andcollecting the continuous filaments in a linear group.

9. The method of processing heat-softenable filamentforming materialincluding the steps of feeding the material in finely divided form intoengagement with a distributor in a walled chamber, discharging thefinely divided material from the distributor by centrifugal forces intoengagement with a surface of the walled chamber, heating the chamber byhigh frequency current to maintain the temperature of the surface abovethe softening temperature of the finely divided material, softening thematerial on the surface by the heat to a flowable state, rotating thechamber, flowing the softened material downwardly along the surface,flowingthe softened material through openings in the surface under theinfluence of centrifugal forces and attenuating the material intodiscrete continuous filaments, continuously flowing heated air at lowvelocity in a region surrounding the chamber, modifying the directionsof movement of the continuous filaments by the heated air, andcollecting the continuous filaments in a linear group.

10. The method of processing heat-softenable filamentforming materialincluding the steps of feeding the .material in finely divided form intoengagement with an elevated distributor in a walled chamber, dischargingthe finely divided material from the distributor by centrifugal forcesinto engagement with a surface of the walled chamber, heating thechamber by high frequency current to maintain the temperature of thesurface above the softening temperature of the finely divided material,softening the material on the surface by the heat to a flowable state,rotating the chamber, flowing the material downwardly along the surface,flowing the softened material through openings in the surface under theinfluence of centrifugal forces to form the material into discretecontinuous filaments, continuously flowing low velocity streamsof heatedair in a region adjacent and surrounding the chamber, continuouslyflowing low velocity streams of air of a lesser temperature in anannular region surrounding the heated air adjacent the rotor. retardingmovement of the continuous filaments outwardly from the chamber by theair streams, and collecting the filaments in a twisted linear group.

11. Apparatus of the character disclosed. including, in combination, asupport, a thin-walled hollow rotor of small diameter and of generallycylindrical shape journally supported for rotation on the support, meansfor rotating the rotor, said rotor wall being formed with a plurality ofcomparatively small orifices, a platform in said rotor rotatable withthe rotor, means for feeding heat-softenable material into the rotoronto the platform, said platform being arranged to distribute thematerial onto the wall region of the rotor, means for heating the rotorto a temperature sufficient to reduce the material to a moltencondition, said rotor being rotated at a speed to project the moltenmaterial. by centrifugal forces through the orifices as continuousfilaments, a plenum chamber disposed adjacent the rotor having an openarea adapted to direct low velocity streams of air into the zone of thecontinuous filaments, means for heating the air prior to its deliveryfrom the plenum chamber, and a barrier surrounding and spaced from therotor arranged to confine the heated air in'the zone of the filaments.

12. Apparatus of the character disclosed including, in combination, asupport, a thin-walled hollow rotor of comparatively small diameterjournally supported for rotation on the support, means for rotating therotor, said rotor wall being formed with a plurality of comparativelysmall orifices, means for feeding heat-softenable material into therotor in particulate form, means within the rotor arranged to distributethe material onto a wall region of the rotor, a first high frequencyinduction heatiug means for heating a wall region of the rotor spacedfrom the orifices to a temperature suflicient to reduce the particles ofmaterial to a molten condition, said rotor being rotatable at a speed toproject the molten material by centrifugal forces through the orificesas continuous filaments, a plenum chamber disposed adjacent the rotorhaving an open area adapted to direct streams of air into the zone ofthe continuous filaments, and means for heating the air prior to itsdelivery from the plenum chamber, a sleeve surrounding and spaced fromthe rotor arranged to confine the heated air in the zone of thefilaments, and a second high frequency induction heating meanssurrounding the rotor and spaced from said first induction heating meansfor heating the Wall region of the rotor provided with the orifices.

13. Apparatus of the character disclosed including, in

13 combination, a support, a thin-walled hollow rotor of comparativelysmall diameter journally supported for rotation on the support, meansfor rotating the rotor, a wall of said rotor being of frusto-conicalshape formed with a plurality of orifices, an elevated platform in therotor rotatable with the rotor means for feeding heat-softenablematerial into the rotor in particulate form onto the platform, saidplatform being arranged to distribute the material onto frusto-conicalwall of the rotor, high frequency induction means for heating the rotorto a temperature suflicient to reduce the particles of material to amolten condition, said rotor being rotatable at a speed to project themolten material by centrifugal forces through the orifices as continuousfilaments, a plurality of annular plenum chambers disposed in concentricrelation having open areas adapted to direct low velocity streams of airinto the zone of the continuous filaments,

heating means for elevating the temperature of the air prior to itsdelivery from the plenum chambers, and a member surrounding and spacedfrom the rotor arranged to confine the heated air in the zone of thefilaments.

14. Apparatus of the character disclosed including, in combination, asupport, a thin-walled hollow rotor journally supported for rotation onthe support, means for rotating the rotor, said rotor wall being formedwith a plurality of small orifices, an elevated platform in the rotorrotatable with the rotor, means for feeding heatsoftenable material intotherotor in particulate form onto the platform, said platform beingarranged to distribute the material onto a wall region of the rotor, ahigh frequency induction heating means surrounding the rotor arranged toheat the wall region of the rotor to a temperature above the softeningtemperature of the material to reduce the material on the wall region toa molten condition, a cylindrical sleeve spaced from and surrounding therotor, means for rotating the rotor to project the fiowable materialthrough the orifices under the influence of centrifugal forces to formcontinuous filaments, a plenum chamber substantially concentricallyarranged with respect to the rotor, said plenum chamber being adapted todeliver low velocity streams of air into the region of the continuousfilaments, means associated with the plenum chamber for elevating thetemperature of the air prior to its delivery from the plenum chamber toestablish a heated environment for the continuous filaments.

15. Apparatus of the character disclosed including, in combination, asupport, a thin-walled hollow rotor of comparatively small diameterjournally supported for rotation on the support, means for rotating therotor, said rotor wall being formed with a plurality of comparativelysmall orifices, an elevated platform in the rotor rotatable with therotor, means for feeding heat-softenable material into the rotor ontothe platform, said platform being arranged to distribute the materialonto a wall region of the rotor, a high frequency induction heating unitsurrounding the rotor and arranged to heat the wall region of the rotorto a temperature above the softening temperature of the material toreduce the materialon the wall region to a molten condition, means forrotating the rotor to project the molten material through the orificesunder the influence of centrifugal forces to form continuous filaments,and a plurality of annularly shaped plenum chambers substantiallyconcentrically arranged with respect to the rotor, said plenum chambersbeing adapted to deliver low velocity streams of air into the region ofthe continuous filaments.

References Cited in the file of this patent UNITED STATES PATENTS2,187,094 Pink Jan. 16, 1940 2,431,205 Slayter Nov. 18, 1947. 2,497,369Peyches Feb. 14, 1950 2,514,627 Cook July 11, 1950 2,863,493 Snow et al.Dec. 9, 1958 FOREIGN PATENTS 202,877 Australia July 5, 1956 1,124,487France Oct. 11, 1956 1,155,519 France Dec. 2 1957 665,606 Great BritainIan. 30, 1952

